A METHOD TO DERIVE THE TIME OF ONSET OF INFECTION FROM SEROLOGICAL FINDINGS

Among the diagnostic problems requiring a retrospective assessment of the time an event occurred is that of screening for primary infection with Toxoplasma gondii acquired during pregnancy. We suggest a method to derive the possible times of onset of infection from a small sequen ce of serological samples by matching them against the knowledge about possible courses of infection. Special care is taken to properly addr ess the relative change of consecutive samples, a nontrivial problem w hen reasoning about sparsely sampled time courses. To investigate the practicability of our approach we conducted a retrospective and a simu lated prospective evaluation based on the samples of 394 pregnancies, randomly selected from our toxoplasmosis database; we could demonstrat e an overall accuracy of 95.7%.